Field of the Invention
The present invention relates to a float type clamping mechanism, more particularly to a float type clamping mechanism by which the workpiece pallet can be stably clamped without shaking happened, so as to ensure machining precision of the workpiece in processing.
Brief Description of Prior Art
For semi-automatic or fully automatic machining operation, whether carrier loaded with workpiece can be releasably clamped on the position of a chuck accurately or not is very important. For example, if the workpiece supporting body is not accurately positioned on the chuck, there might be the danger of position deviation of the workpiece, and this may result in deviation or inaccuracy of workpiece dimension, of course this may cause extremely serious destruction.
Usually, this type of clamping mechanism is substantially one similar to a positioning means as in TW Patent Pub. No. I455790 B for positioning an object respectively in axial direction along X-axis, Y-axis perpendicular to X-axis, and Z-axis orthogonal to X-axis and Y-axis, and allows the object to be positioned on a plane parallel to X-axis and Y-axis and rotationally in Z-axial direction. A fastening member can releasably hold stationary member firmly in place. When the stationary axial rod of the stationary member is inserted into the fixing hole of the fastening member, a gap is formed between a first reference surface of the stationary member and a second reference surface of the fastening member, and the outer surface of the pyramid portion of the stationary axial rod is in fit connection with the inner surface of the fixing hole, and the object is positioned in X-axis and Y-axis directions. When the fastening portion of the fastening member pulls the stationary axial rod, the first reference surface and the second reference surface are contacted with each other so that the pyramid portion or the fixing hole generates elastic deformation. Further, the stationary axial rod is pulled further into the fixing hole so as to maintain the fit connection between the outer surface of the pyramid portion and the inner surface of the fixing hole.
Alternatively, this type of clamping mechanism is a fixture disclosed in TW Patent Pub. No. I432282 B, especially including a chuck having a locking mechanism for positioning a workpiece pallet by a releasable method. Instead, this type of clamping mechanism can be a rapidly releasable workpiece jig disclosed in Germany Patent DE 196 36 375 A1; or a clamping device disclosed in TW Patent Pub. No. 592882 B [JP 2003200326 A], comprising a clamping chuck and a workpiece supporting body which is releasably mounted on the clamping chuck, the workpiece supporting body including a flat bottom surface and a clamping pin extending from the flat bottom surface; the clamping chuck including a central opening for receiving the clamping pin of the workpiece supporting body and a conical insertion part; the clamping pin including at least one surface part, in which the shape of the surface part corresponds to the shape of the conical insertion part so as to correct the position of the clamping pin in X and/or Y direction; the clamping chuck further including a clamping mechanism for clamping the clamping pin of the workpiece supporting body in the central opening, and at least one surface part serving as a fastening member in Z direction, characterized in that the clamping pin is marked with inscription of dimension, before starting the clamping mechanism, a gap may exist between the flat bottom surface of the workpiece supporting body and the surface part of the clamping chuck serving as the fastening member in Z direction; after the clamping pin of the workpiece supporting body is inserted into the central opening of the clamping chuck and the at least one surface part of the clamping pin is engaged into the conical insertion part of the central opening, the position of the clamping pin with respect to the clamping chuck in X and/or Y direction is corrected; once the clamping mechanism is started, the clamping pin and/or the region around the central opening of the clamping chuck are elastically deformed so as to pull the clamping pin further into the central opening, simultaneously the workpiece supporting body moves toward the surface part serving as the fastening member in Z direction until the flat bottom surface of the workpiece supporting body rests on the surface part of the clamping chuck serving as the fastening member in Z direction.
It can be understood from the above prior art that ordinary clamping equipment is mainly to be designed whether the workpiece support body (pallet) is accurately locked/released or not. However, when workpiece needs more precise dimensions, the workpiece support body (pallet) should be kept in unshaking status when in machining. Thus, the workpiece support body (pallet) and the clamping equipment further need high-precision combination design in addition to clamping. Therefore, when producing clamping equipment or workpiece support body (pallet), the combination precision of these two relative to each other should be kept below the range of 0.01 mm. In consequence, this manufacturing process may result in cost increase, time and labor consuming and high failure rate, and then service life is short and elimination rate is also high.